Could ET mask a diagnosis of Vitamin B12 deficiency/Pernicious anaemia?

[Cb1001]

I have an ET JAK2 mutation diagnosis (on aspirin) and have some neurological type symptoms that are similar to those associated with a Vit B12 deficiency. Athough I'm now taking a B12 supplement, I was wanting to see if I could get a B12 injection in case my issue related to an inability to absorb B12 , but my GP seems reluctant to do this as my serum B12 level is still within the standard range and not 'low'.

I am aware of the websites/references/journal publications that others have posted on here and in the PA forum, that have indicated that patients who had myeloproliferative disorders could have vitamin B12 deficiency, despite 'high' serum vitamin B12 levels. When they say 'high' I'm not sure if that means a significantly high level above the range or if could just be within the standard range but 'high' for someone with a deficiency (if that makes sense) and hence not considered deficient . I have mentioned my symptoms to my haematologist, who didn't think they were due to my ET and I think he has previously said to me that I don't have PA.

My GP has asked me to have another B12 test but given I've been taking supplements I'm not convinced that this is going to show anything if it is just a serum test.

I therefore wondered if anyone has ET and a PA diagnosis and what were the main adverse blood test results that you had that diagnosed this. I'm aware that you can test for methylmalonic acid (MMA) and intrinsic factor antibodies, but suspect that they are not routinely provided by NHS?

I hope that makes sense.